CONFERENCE ANNOUNCEMENT: SECOND INTERNATIONAL CONFERENCE ON CIRCUMPOLAR VEGETATION CLASSIFICATION AND MAPPING

SCOPE: The conference will focus on issues related to classification, mapping, and modeling of vegetation in Arctic tundra
regions. The last major gathering of Arctic vegetation scientists was at the International Conference on Classification of
Arctic Vegetation, held at the Institute of Arctic and Alpine
Research, Boulder CO, USA, 5-9 March 1992. Since then there has
been considerable progress toward classification and mapping as
a means of understanding the Arctic as a single geo-ecosystem,
and to aid in numerous efforts to model the response of vegetation to climate and land-use changes.

The classification portion of the conference will be primarily
devoted to vegetation surveys of syntaxa or monographs on special areas or regions of the Arctic. Floristic and taxonomic
papers might be accepted if they are directly of importance to
vegetation science.

The mapping portion will focus on circumpolar and large-regional scale mapping efforts. Papers directed at circumpolar
issues are particularly welcome. Members of the Circumpolar
Arctic Vegetation Mapping (CAVM) project are encouraged to
present regional maps derived from the CAVM at 1:4M scale with
legends that show the dominant plant associations or plant
community types.

MARINE AND TERRESTRIAL ECOSYSTEM LINKAGES: THE MAJOR ROLE OF SALMON AND BEARS TO RIPARIAN COMMUNITIES

Introduction

Throughout the Pacific Rim, the yearly migration of anadromous
salmon provides a pulse of nutrients for a diverse range of
marine, freshwater and terrestrial organisms. Jeff Cederholm
from the Washington compiled literature on marine food web
interactions and noted that at least 130 species of vertebrates
use migrating salmon as a food source (Cederholm et al. 2002).
John Stockner, Ken Ashley and colleagues from Vancouver and Mark
Wipfli and colleagues from Alaska have shown major increases in
primary and secondary productivity in stream habitats from the
contribution of salmon carcasses to the stream channels (Wipfli
et al. 1998; review in Stockner and Ashley 2003). At river
mouths from California, Oregon, Washington, British Columbia and
Alaska, black bears and brown bears congregate during autumn
migration and forage on salmon, acquiring some 70% of their
annual protein consumption during this short period (Reimchen
1992, 1994, 2000; Gilbert and Lanner 1995; Hilderbrand et al.
1999). Coastal wolves shift from their major diet of deer in
summer to that of salmon during the spawning migration (Darimont
and Reimchen 2002). Numerous birds including eagles, gulls,
ravens and crows also exploit the salmon nutrients. This
seasonal pulse of marine nutrients is spatially and temporally
associated with a major increase in diversity and abundance of
animals throughout the west coast of North America.

These investigations parallel several other research programs by
colleagues at UBC and at US institutions including those in
Alaska and Washington but our lab has focused on identifying the
contributions of salmon nutrients to the multiple trophic levels
within terrestrial habitats. During an investigation of black
bear feeding activity in the autumns of 1992, 1993 and 1994 on
the south end of Haida Gwaii, I observed individual bears carrying salmon from the stream into the forest where feeding could
occur without interference from other bears. Over the eight-week
spawning period, each bear transferred up to 700 salmon into the
forest leaving remnants of each carcass on the forest floor
(Reimchen 1994, 1998, 2000). Most of this foraging occurred
during darkness, and by the end of the spawning period, over
5000kg of carcass remnants had accumulated in a 50 m band over
the kilometer of stream where spawning occurred. These abandoned
tissues were used by a wide diversity of scavengers including
gulls, eagles, ravens, crows and marten as well as by large
quantities of invertebrates of which fly maggots were the most
abundant. While collecting this information on carcasses in old
growth forest adjacent to the salmon stream, I suspected that
the prevalence of decomposing carcasses as well as the waste
products from bears and other scavengers would provide a
nutrient source for vegetation. These early observations became
the focus for a greatly expanded research program in my lab
funded primarily by the David Suzuki Foundation and the Friends
of Ecological Reserves which now entails studies from 120 watersheds extending from Clayoquot Sound on Vancouver Island to the
coastal mainland near the Broughton Archipelago north to the
grizzly bear sanctuary at the Khutzeymateen River on the northern end of the province and across to Haida Gwaii. Throughout
the BC coast, black bears and brown bears transfer carcasses
into the forest, occasionally to distances of 150 m away from
the stream, particularly on steep gradient slopes. We are quantifying the contribution of salmon nutrients at multiple levels
of the terrestrial ecosystem including bryophytes, herbs, shrubs
and conifers, soil and canopy invertebrates including insects,
and to vertebrates such as songbirds, black bear, grizzly bear
and wolves (general description of this research, graduate
projects and pdf files of publications are available at
http://web.uvic.ca/)

The major natural historical observation to emerge from our
studies throughout the coast, and one that is familiar to all
coastal First Nations, is that the diversity of predators and
scavengers that congregate in estuaries and rivers during spawning migration is directly related to the density of salmon in
the river. On the British Columbia mid-coast, highly productive
rivers have salmon spawning density as high as 50,000 per
kilometer of river and associated with these salmon are congregations of up to 10 wolves, 15 bears, 50 bald eagles, 100's
of crows and ravens, up to 4000 gulls and numerous song birds.
For each of these taxa, it is largely the spawned-out salmon
carcasses that provide the major food source over a two-month
period. Blowflies are the major consumers of the carcass remnants. Usually within three to four days after abandonment by
the bears, the carcasses are a mass of maggots. The entire soft
tissues will be consumed within a week after which the maggots
disperse onto the surrounding substrate and bury into the surface mosses. Maggot densities in the moss substrate commonly
reach 100 /m2. One of my graduate students, Morgan Hocking, has
found that the majority of adult blow flies collected in
riparian forests in spring and summer have major isotopic enrichment in 15N and 13C signatures, confirming their trophic
origin from salmon carcasses the previous autumn. Hocking has
also sampled other invertebrate taxa including earthworms,
beetles and spiders from multiple trophic levels from habitats
above and below waterfalls and observed major enrichment of 15N
below the falls compared with above the falls. The extent of 15N
enrichment was greatest at higher trophic levels. This was not
due to direct consumption of salmon carcasses but rather due to
indirect consumption from salmon-derived nitrogen subsidies to
litter, soil and vegetation N pools. (Hocking and Reimchen 2002)
The total nitrogen in the invertebrates could be partitioned to
source and these results showed that 18-78% of nitrogen was
originally derived from salmon, with specific levels depending
on species and watershed. Total biomass of insects is up to an
order of magnitude higher in forests adjacent to salmon spawning
areas relative to riparian forests without access to salmon.
Another graduate student, Katie Christie, has now shown that
songbirds are more abundant in forests adjacent to salmon spawning areas and have major enrichment in 15N isotopic signatures
during the late summer derived from consumption of blowflies as
well as higher trophic levels invertebrate predators such as
spiders. Research by other members of our lab including Chris
Darimont who is investigating coastal wolves has demonstrated
that samples of hair yield very clear evidence for a seasonal
shift in diet from terrestrial prey to salmon (Darimont and
Reimchen 2002). Another lab member, Dan Klinka, is investigating
the salmon foraging activity of Kermode bear as a comparison
with earlier work on brown bear (Klinka and Reimchen 2000).

One of the surprising results from our studies is the extent of
salmon nutrient uptake by riparian vegetation. Mosses and liverworts comprise the dominant ground cover throughout temperate
rainforest ecosystems in the North Pacific Rim and these are
essential to numerous edaphic processes including temperature
regulation and moisture retention. Bryophytes commonly absorb
nutrients from precipitation and canopy through fall as well as
from underlying soils and N-fixers. Our lab, in particular Chad
Wilkinson, has investigated the contribution of salmon- derived
nitrogen to eight species of mosses and liverworts
(Rhytidiadelphus loreus, Hylocomium splendens, Sphagnum
girgensohnii, S. squarrosum, Rhizomnium glabrescens,
Kindbergia oregana, Conicephalum conicum and Pellia
neesiana) above and below waterfalls that are barriers to
salmon migration and at a control river without salmon. Overall,
Delta 15N signatures ranged from 2% to 7% higher below the falls
near the salmon stream than above the falls or at the adjacent
control watershed that had no salmon. Delta 15N values were
highest in mosses from sites where salmon bone fragments were
present in the substrate, indicative of a carcass transfer
during previous years. Isotopic values were also high in mosses
adjacent to wildlife trails. We also examined percent nitrogen
in the moss tissues as nitrogen is generally considered to be a
proxy for photosynthetic rate and is the principal limiting
nutrient in temperate forest ecosystems. We observed increased
levels of tissue nitrogen below the falls and in sites where
salmon carcasses were prevalent indicating microspatial
heterogeneity in the salmon nutrient pools of these forests.
Moss species richness and prevalence of nitrogen-rich soil
indicators were also highest in forests adjacent to the salmon
stream (Wilkinson et al. submitted).
We have examined the contribution of salmon nutrients to other
riparian vegetation including Blechnum spicant, Menziesii
ferruginea, Oplopanax horridus, Rubus spectabilis, Vaccinium alaskense, V. parvifolium and Tsuga heterophylla.
15N values were enriched by 1.4% to 9.0% below the falls depending on species and watershed, indicating that 10% to 60% of
tissue nitrogen was marine-derived (MDN). As well, %N in foliar
tissues was slightly higher below the falls, with the majority
of variance occurring between vegetation species. Of interest is
that salmonberry, one of the common riparian shrubs, had the
highest percent tissue nitrogen of the six most common riparian
species (Mathewson et al. 2003; Reimchen et al. 2003). Community
structure also differed with higher incidence of nitrogen-rich
soil indicator species below the waterfalls.

We have also been able to identify historical signatures of
salmon-nutrient loading to the riparian zone through analyses of
yearly growth rings taken from cores of ancient trees. This has
been approached in two methods 1) a direct measurement of yearly
growth rate and 2) analyses of 15N signatures and percent N
levels in individual rings. These ongoing studies yield clear
evidence for increased average growth of conifers with access to
salmon. We tested whether there was a yearly growth signature
that correlated with yearly differences in actual salmon counts
made by Department of Fisheries over the last 50 years. Some
trees show very strong correlations between yearly salmon abundance and tree growth when lagged from 1 to 3 years but most
trees nearby show only weak or no such relationships. The same
trend occurs with analyses of 15N signatures in the tree rings.
Some trees have high lagged correlation between salmon abundance
over the last 50 years and 15N levels in the rings yet adjacent
trees show no associations. We are currently trying to identify
the best habitat predictors for these trees that show excellent
tracking between salmon abundance and nitrogen signatures.
Currently, I have obtained 1150 cores of ancient trees in 120
watersheds throughout coastal British Columbia and these cores
have the potential of yielding a 300-year history of salmon
abundance and riparian nutrient loading on our coast.

These investigations are still in their infancy but the emerging
data provide a reasonably clear picture of a multi- trophic
level linkage between marine and terrestrial ecosystems. When up
to 70% of the nitrogen in mosses, herbs, shrubs, ancient trees,
canopy insects, songbirds and bears in coastal forests is
derived from the central Pacific ocean via the life history of
the salmon, the implications of spatial and temporal differences
in salmon abundance are substantive. Since 1880, salmon have
declined by approximately 80-90% on the west coast of North
America due to the combination of over-fishing, large scale
commercial logging, dam construction as well as fluctuations in
oceanic productivity. What effects if any have there been of
this decline and would they be detectable if they did occur? Our
studies and those from other labs have found lower levels of
estuarine, stream and riparian community diversity in watersheds
without access to salmon and these differences are also evident
within rivers above waterfalls that are barriers to salmon
movement. We have observed that above waterfalls, there are
lower species diversity of mosses, lower incidence of nitrogen-rich plant indicator species, lower biomass of insects, lower
densities of songbirds and lower growth rate of conifers. This
suggests that the estimated 80-90% reduction in salmon abundance
throughout the coast will lead to a reduction in carrying
capacity and shifts in the plant and animal community structure
that converges to that resembling watersheds without access to
salmon.

Energy, diet selection and
restoration of brown bear populations. Pp. 231-240. in
Proceedings of the 9th International Conference of Bear
Research and Management. Pateris: French Ministry of the
Environment an the Natural History Museum of Grenoble.

For over thirty years, Hans Roemer's thesis on forest classification on the Saanich Peninsula has been available only as
photocopies at the University of Victoria library, on microfilm
(e.g., the University of British Columbia library), or as
photocopies of photocopies (e.g., Library of the British Columbia Ministry of Forests).

This spring I managed to convince Hans that his thesis is still
a relevant source of valuable phytosociological information and
he gave his consent to putting his thesis on the British Columbia Ministry of Forests web site as a .pdf file. Rick Scharf and
Steve Netherton scanned the original copy and converted it to
pdf, and the BC Ministry of Forests library supervisor Roxanne
Smith put it on their library web site. Many thanks to all
people involved in this project!

Here is the Abstract of Hans Roemer's thesis:

The forest vegetation on the Saanich Peninsula, Vancouver Island, is classified in 7 associations, 12 subsassociations and
20 variants, on the basis of 400 releves. Communities are distinguished by diagnostic species groups, which were derived by
computer sorting of vegetation tables (Ceska and Roemer, 1971).
The rationale of decisions in the classification process is
discussed both in terms of floristic differentiation and numerical similarity.

Detailed descriptions of each community include its physiognomy
and life forms, its diagnostic species groups, community statistics and habitat. Extensive vegetation tables form an important
part of this work.

Relationships of forest vegetation to environmental factors are
considered at the level of single species, species groups and
communities. Major habitat variables are correlated with species
and species groups through non- parametric statistical methods.
The main floristic gradient exhibited in ordered vegetation
tables is recognized to be correlated with general moisture
conditions. Most other environmental variables appear to coincide with and partly depend on moisture conditions.

Soils, watertables and stand climates are described for subjectively selected stands representative of the communities. Soils
are classified on the basis of 40 detailed soil profiles and 150
routine examinations by soil auger. Communities are strongly
correlated with morphological types of profiles, but are only
partly correlated with soil units of the current Canadian classification. Distinctive watertable types are found for the moist-site communities. Important differences are shown in maximum
water levels, duration of high water levels, and range of
watertable fluctuation for three major communities. Prediction
of watertable conditions according to species composition is
proposed.

Succession and climax are discussed. The forest community on
mesic sites is the Pseudotsuga-Berberis association on Orthic
Dystric Brunisols. Communities of the driest sites are the
Quercus-Erythronium and the Arbutus-Pseudotsuga associations, those on wettest sites the Alnus-Athyrium and Populus-Pyrus associations. The former occur on Lithic Sombric and
Lithic Dystric Brunisols, and the latter on Organic soils and
Gleysols. Only fragments of the Pinus contorta bog forest
remain.

A reconstruction of the pattern of the original forest communities is attempted for valley sites now under agricultural
use. The evaluation of an open, park-like landscape in the
Quercus vegetation complex is interpreted as a combined result
of subregional climate, microclimate and early human history.